Check-valve.



PATENTED JAN. 30, 1906.

P. E. TEN EYGK.

CHECK VALVE.

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MTTORNEY' UNITED srs n'r FFIGE.

CHECK-VALv/E.

Specification of Letters Patent.

Patented Jan. 30, 1906.

Application filed November 10, 1902. $erial No. 130,720.

To all whom it may concern:

Be it known that I, FRANK E. TEN Event, of Auburn, in the county of Cayuga, in the State of New York, have invented new and useful Improvements in Check-Valves, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to improvements in check-valves, and refers more particularly to that class which is employed in connection with air-compressors.

Certain forms of check-valves which may be adapted for use with hydraulic compressors may possess features in common with certain other forms of similar valves used in air-compressors, and yet these common fea tures in one use may be wholly inadequate to the requirements in the other use.

In the compression of air and other gases, particularly under a hi h degree of pressure, one of the most difficult roblems has been how to prevent injurious eating of the cylinders and pistons of the compressors without the use of water-jackets and other cooling devices;

After numerous experiments with various known forms of check-valves, both for hydraulic and air compressors, applicant has discovered that the primary cause of this heat was the compression of the air before the back pressure could be overcome and that if the period of resistance from the back pressure could be lessened so that the com.- pressed air could vent through the checkvalve at the initial movement in the compression-stroke of the piston a more steady circulation of air would take place and the heating resulting from compression would be reduced to a minimum insufficient to injure either the cylinder or piston even when a leather packing is employed on the piston.

My first object, therefore, is to obviate the injurious heating of the cylinder and piston without water-jackets or other cooling means by constructing a check-valve so that it may be unseated against any degree of back pressure at the initial movement of the compression-stroke of the piston.

Referring to the drawings, Figure 1 is a vertical section of a check-valve embodying the features of my invention. Figs. 2 and 3 are sectional views taken on lines 2 2 and 3 3, Fig. 1. Figs. 4, 5, and 6 are detail views of the outer shell or casing, the inner bushing or valve-guidc, and the valve.

Similar reference characters indicate corresponding parts in all the views.

This invention comprises an outer shell or casing 1., a valve 2, and a bushing or plug 3, all of which parts are of suitable size and material adapted for the purpose for which the device is used.

The shell 1 is adapted to be secured in an upright position to an air-compressor or to some connection leading from its outlet, one end, as the lower end, being threaded externally at 4 for this purpose and provided with a central inlet 5 and a tapering valve-seat 6 for the valve 2.

The upper end of the shell is open and is usually threaded internally at 7 to receive a threaded cap 8, which serves to retain the bushing and permit the parts 2 and 3 to be removed or inserted when desired.

Leading laterally from the interior of the shell near its upper end is an outlet-passage 9, from which the compressed air may be diverted to any locality to effect the work intended.

The interior of the shell 1 is carefully bored from its upper end inwardly to a point below the outlet-opening and above the valve-seat 6 to form a smooth cylindrical guide or bearing 10 for the bushing 3, which is fitted airtight therein, the internal threads 7 being cut in the walls of the upper end of the bore to permit the bushing to be readily removed when desired. This cylindrical bearing 10 terminates at its lower end in an annular seat or shoulder 11, from which seat the interior of the shell is further carefully bored with a reduced diameter to form a cylindrical guide or bearing 12 for the valve 2, the axes of said guides or bearings being coincident with each other and with the inlet 5 and valve-seat 6.

The valve 2 consists of a lower head 18 and a tubular stem 14, rising from the head to a a point above the lower wall of the outlet 9, the head 13 being guided in the bearing 12 and is provided with a tapering face 15 for engaging the valve-seat 6 and with a cylindrical bearing-face 16, which is ground to a sliding fit with the cylindrical bearing 12 to prevent the leakage of air at the sides of the valve. nular groove 17 in the periphery of the tapering face 15 and with small air-ducts 18, leading from the groove to the base of the tubular stem 14, so that when the valve is unseated the air will readily pass into the interior of the tubular stem.

This head 13 is formed with an an The stem 14 is considerably smaller in diameter than the head 13 and is provided with a lengthwise passage 20, leading from the ducts 18 to the upper end of the stem, said upper end being formed with lateral passages 21, communicating with the outlet passage 9. This lengthwise passage 20 of the stem is preferably of less diameter than that of the inlet 5, and it is this feature which renders the valve operable by the compressed air from the compressor against the back pressure at the initial movement of the compression-stroke of the piston, (not shown,) the principle being that the back-pressure head being less than the head of the valve which is exposed through the inlet 5 the exerted force of compression to unseat the valve against the resistance of back pressure is proportionately less as the compression-head of the valve is greater than the back-pressure head.

The bushing 3 is formed with a central opening 25, which receives and closely fits the periphery of the stem 14 to form an airtight joint, and is also provided with branch passages 26, connecting the lateral passages 2 1 with the outlet 9. The periphery of this bushing is also ground and fitted in the cylindrical bearing 10, and its lower end normally rests on the annular shoulder 11. It is thus evident that by closely fitting these parts 2 and 3 in their respective bearings the air is con fined within the proper channels and is prevented from leaking at the joints, and at the same time the valve is caused to move in exact alinement with its axis, and thereby seats itself with more precision than would be the case if not guided in the manner described.

I have described this valve as being used in an upright position; but it may be attached in any other position, in which case I use a spring 30 to return and hold the valve to its seat,

Havin thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. A check-valve for air-compressors comprising a shell having an inlet and valve-seat in one end and an outlet in one side and formed with a central bore, and an annular seat at one end of the bore between the inlet I sinisr and outlet, a bushing having an air-tight fit in said bore and formed with a central guide opening of less diameter than the inlet and communicating with the outlet, a valve play ing between the inlet and adjacent end of the bushing and provided with an annular groove facing the valve-seat at the inlet, said valve having a hollow tubular stem fitting with an air-tight fit in the central opening of the bushing and having lateral passages leading from its interior to the annular groove, the interior of the tubular stem also communicating with the outlet.

2. A check-valve for air-compressors comprising a shell having an inlet and an outlet and provided with a valve-bore of greater diameter than the inlet, a bushing fitting in the shell and having a central opening of less diameter than the valve-bore, an inlet-valve fitting air-tight in the valve-bore and having an annular groove facing the valve-seat, said valve playing between the inlet and adjacent end of the bushing and having a hollow stem fitting with an air-tight sliding fit in the central opening of said bushing and having its interior communicating with said annular groove and outlet.

3. A check-valve comprising a shell having an inlet and an outlet, a valve seated in the inlet and having a lateral passage opening to the inlet when the valve is open, said valve having a sliding air-tight fit in the shell between the seat and outlet and provided with a reduced hollow stem having one end communicating with said passage and its other end opening to the outlet, and a bushing fitted air-tight in the shell and having a guide-opening receiving the valve-stem and forming an air-tight joint therewith, and an annular shoulder in the shell between the valve-seat and outlet to limit the endwise movement of the bushing, said bushing cooperating with the valve to limit its movement.

In witness whereof I have hereunto set my hand this 4th day of November, 1902.

FRANK E. TEN EYCK.

Vitnesses:

F. LEE ROGERS, H. E. CHAsE. 

